Forced air cooling delays pericarp browning and maintains post-harvest quality of litchi fruit during cold storage

The present study was conducted to study the potential of forced air cooling (FAC) on the post-harvest quality of litchi fruit. Bunches of 'Dehradun' litchi cultivar were collected after they reached full physiological maturity and they attained full rosy red color. After that, the fruits were destalked, stored in plastic crates, and treated with FAC for 2, 4, and 6 h. The fruits that had not been exposed to FAC were used as a control. Temperature of fruit pulp was regularly monitored with a digital thermometer for requisite period of time. Immediately after FAC treatments, the fruits were packed in corrugated fiberboard boxes (CFB) and stored in a walk-in-cold room maintained at temperature 2-3 degrees C and RH of 90-95%. The stored samples were evaluated periodically at weekly intervals up to 4 weeks for various physiological, biochemical parameters and enzymatic activities. The study demonstrated that, FAC (6 h) treatment effectively prolonged the storage life of litchi fruits for about 14 days over the control. The results revealed that litchi fruits subjected to FAC for 6 h maintained lower physiological loss in weight (4.30%), browning index (2) and improved pericarp color, retained higher firmness (108.5 g force), organoleptic score (6.80), TSS (18.85oB), acidity (0.32), anthocyanins (0.25 increment A/g FW), total phenols (234.95 mg/100 g) and also maintained the lowest PPO enzyme activity (156.60 unit/min/g FW) as compared to the control and other treatments. The aim of current study was that pre-cooling would delay the onset of senescence, preserving the quality of litchi fruits during storage and distribution.